Beflectoe



W. V. FOLEY.

REFLECTOR.

APPLICATION FILED MAR- 12. 1918.

Patented Mar. 7, 1922.

2 SHEETS-SHEET l- W. V. FOLEY.

REFLECTOR.

APPLICAT .12, I918- 1,40 8,875. Patented Mar. 7, 1922.

I 2 EEEEEEEEEEEE 2.

H UNITED STATES WILLIAM VINCENT FOLEY, OF NEW BRUNSWICK, NEW JERSEY.

PATENT OFFICE.

REFLECTOR.

Specification of Letters Patent.

Patented Mar. '7, 1922.

;Application filed March 12, 1918. Serial No. 222,004.

To all whom it may concern: 7

Be it known that I, VVILLIAM VINCENT FOLEY, a citizen of the UnitedStates, residing at New Brunswick, in the county of Middlesex and Stateof New Jersey, have invented certain new and useful Improvements inReflectors, of which the following is 'specification.

This invention relates to reflectors for use in apparatus formotion-picture projection and other purposes, and is especially usefulin effecting the reflection of light rays from an incandescent electriclamp through a condensing-lens on a moving-picture film or other objectorimaterial to be either illumi-' nated or subjected to the action ofreflected light rays passed through a condensing lens.

WVhile the present invention is an improvement in reflectors, yet asthey are of a special character of great and novel utility in special ifnot all uses, I set forth my present invention in an; apparatus and incooperating relations to other things in order to show forth clearly themerits of the present invention. Said apparatus is not herein claimed,as it forms the subject-matter of my application Serial No. 217,083 ofeven date, filed Feb. 1 1, 1918, on which Patent No. 1,286,269 wasgranted December 3, 1918.

The .objects of the invention are to conserve and utilize a maximumquantity of light emanating from an incandescent electric lamp; and toproduce a reflector of high efficiency and economy for use inmotion-picture projecting machines; or for use in treatment of anymaterial or object requiring exposure or subjection to light rays whichtravel from a source oflight through any suitable condensing lens. As Ido not know all the industries in which my reflector may be practicallyuseful, I take pains herein not to limit my invention merelyto use inmotion-picture projecting machines, which use however is one that I havegiven particular attention to and onein which the invention isconsidered to be of very marked advantage'.

In the accompanying drawings forming a part hereof and illustrating theprinciple of this invention in the best mode now known tome of'applyingthat principle,

- Fig. 1 is a central lengthwise vertical section of the preferred formofapparatus in which my new reflector is installed when it is used formotion-picture projections;

Fig. 2 is a front'end, and

Fig. 3 a rear end elevation, and

Fig. 1 a side elevation of the preferred form of the zone-shapedreflector removed.

Assuming that there is used in apparatus containing the presentinvention, a T-20 bulb, 600 watt, 2() ampere, 30 volt, Mazda C lamp suchas is well'known for projection service; also that such lamp has amaximum efficiency of about 1.2 candle power per watt, or 720 candlepower in all; also that a suitable condensing lens is used; and that inoperation with the incandescent filament there is also used a suitableconcave reflector back of the lamp and an outwardly-flaring facetedreflector that is approximately concentric with the point of light whichis forwards of the concave reflector, the outwardly flaring reflectorhaving its large end extending towards the condensing lens; and assumingalso that the reflecting facets are 76 in effective number as hereinshown in the preferred form of the outwardly-flaring .reflec tor, andthat each such facet reflects an image of the incandescent filamentwhich is also reflected in the concave mirror,--we have the followingapproximate results:

The point of light in operation with the concave reflector will yieldabout 80% of the candle power of the lamp, or 576 candle power. And eachfacet reflection will yield about 10% of the candle poweryielded by thepoint of light in operation with the concave 1nirror,-or 7 6 times 10%of 576, which equals 137 7 .6 candle power. The latter being added tothe candle power yielded by the point of light from the concave mirror,gives a total candle power reflected through the condensing lens ofabout 4953.

Such a theoretical total useful candle power so obtained is comparablein ultimate effect with that often obtained by the use of an ordinaryarc lamp; makes it possible to substitute incandescent for are lights inmotion-picture outfits in many installations and with importantadvantages as regards safety, I

My new reflector comprises in its pretom opening of the zone-shapedreflector subtends about 64 of the surface of a sphere, and the width ofthe annulus from its smaller end to its outward end measures about 43along thecircumference of the sphere. Preferably the larger end ofthezone-shaped reflector is provided with a forwardly-extending conoidalrim the inner surface of which is at an angle of 25:1- to a tangentialline parallel with the axis, the rearward spherical and the forwardconoidal portions being preferably integral and together having asurface measurementcorresponding to 180 along the surface of a sphere.

-Referring to the drawings, 1 is a supporting frame 'or casing shown ina form com monly known as a lamp house; 2 an incandescent electric lampbulb having a threaded socket member 3 which screws into a verticalinteriorly and exteriorly threaded socket member 4 that is lengthwiseadjustable in a collar 5 fixed to the upper wall of the lamp houseconcentrically with a hole through the wall. The lamp filament isindicated by 7. Forwardly of the lamp at a proper distance understood byall skilled in the art, the lamp house is provided with aforwardly-extending lens tube 8 wherein is placeda duplex condensinglens comprising in the preferred form of the invention a pair ofplano-convex lenses 9, 9 spaced apart with their convex sides opposed.The long axis of the lamp is at right angles to the principal focal axisof the duplex condensing lens, or what is the same thing, to the axis ofthe lens tube. The inner side of the bottom wall ofthc lamp houseisprovided with a lengthwise-extending dovetailed groove forming aguideway 10 parallel and opposed to a prolongation of the axis of thelens tube; The upstanding support 11 of a forwardly and outwardlyflaring tubular reflector which in its preferred form is the annularspherical zone-shaped reflector 12 hereinafter more particularlydescribed, has a dovetail foot 13 which fits slidablyin the dovetailguideway. The support ll has a hole through which the front end portionofan adjusting IOdll is loosely mounted and held inplaceby a head 15 atthefront and acollarldat the rear side of the support; The adjusting rodis rearwardly threaded at 17 and passes through a thread ed'boss 18 inthe rear end wall of the lamp house exteriorly of which it has a knurledheadvl9z1 Back of the-annular, spherical the condenser lens tube isperpendicular.

This parabolic reflector is held in a crosssectionally round support 21to the back side of whicha rearwardly-extending adjusting rod 22 isfixed, the rod being rearwardly threaded at 23 and passing through aninteriorly-threaded boss 24: fixed in the rear wall of the lamp houseexteriorly of which it has a knurled head 25. When parabolic reflectorshaving perforations through which lamp sockets are inserted are used, aloss of reflected rays occurs.

The diameter of the parabolic mirror support 21is slightly'less than theinterior dia'meter of the rear end opening 26 of the annular sphericalzone-shaped reflector, and theparabolic mirror may bemoved in and outthrough such opening 26 for the relative adjustment of the reflectingsurfaces of the parabolic and zone-shaped reflectors. Rel-l atively tothe filament orpoint of light, theZone-shaped reflector is adjustableby'the screw 14 and the parabolic mirror is adjustable by the screw'23',the filament being adjustable to the principal focal axis of thecondenser lenses by the threaded socket member 6 in the fixed collar 5.

The lamp house is desirably ventilated by means ofanair-pipe 27 thedischarge end of which is adjacent the metal lampsocket members withinthe chamber of the lamp house, the upper wall of which is provided withan air-escapeport '28 between which and the discharge end of theair-pipe the socket members are located. Exteriorly of the lamp housethe air pipe is provided with a fan 29 which draws exterior air into thepipe and forces it into the metal socket members, the ,cooling currentthus" set up entraining air within the chamber and. forcing it throughthe escape port. The parabolic reflector casing and both reflectors areout of contact with thelamp house walls. The parabolic reflector and theinterior wall of the zone-shaped reflector are each'out of contact withthe lamp bulb, and the front brim of the zone-shaped reflector is formedwith an edge recess 30 whereby thezone shaped reflector atits largerfront end can be-positionedrelatively to the filament. or point oflight, with the edge .wall of the recessBO preferably out of contactwith the socket member of'the lamp. Thus' air spaces are obtainedbetween the reflectors, the lamp,'and the lamp house walls, and therising hot air within the lamp house chamber and around the reflectorsand the lamp is entrained by the forced air current at the top of thechamber, andforced out through the port 28. Overheating of'the lamphouse chamber resultsin 1 undue shortnessof lif of electric'lampstherein andalso tends to impair the silvering of the reflector backs orexterlor surfaces when the reflectors are of silvered glass. I

What I have above termed an annular spherical zone-shaped reflector is amost important feature of my invention, but while formor shape is of theessence of its utility,

I do not wish to be understood from the following particularity ofdescription as i11- tending to limit my invention in any degree beyondwhat the state of the prior art may legally require; and I point outthat the i the parabolic reflector are separate reflectors as abovedescribed, the annular zone-shaped I reflector'is primarily anexteriorlyspherical zone measuring (Fig. 4) about 43 from a at' its smallestdiameter to b at its largest diameter; theopen .smaller rear opening ofthe reflectorlbeing subtended by an arc of 64 as indicated by theconcave or parabolic mirror. The larger front end of the reflector ,3forward of the diameter at b has an out wardly flaring integral conoidalbrim 31 the outer face of which is at an angle of 252; to a line tangentto the point b, and the width of this angular or conoidal brim from 6 toc is such that the annular zone-shaped reflector as a whole is anapproximate hemi, sphere in the sense that the front edge of thereflector as a whole is at the diameter of a sphere. I V Both surfacesof the conoidal brim 31 and of the spherical zone-shaped portion of thereflector are preferably formed with a plurality of rows'of flat-facedreflecting surfaces 01' facets 32, each rowlextcnding from the smallerend of the reflector to the out ward edge of the. conoidal brim. Theexterior facets in each annular series are at an angle one to the other,and the exterior facets of the same series are also at an angle one tothe other, and the facets in each exterior and each interior annularseries are severally at an angle to an adjacent facet in one or moreother series. 1 As shown there are fourteen rows of five complete facetseach, and two rows of three complete facets each, four facets beingpractically lost by the cut-out forming the edge recess 30.

This annular flaring reflector, if made of glass silvered on itsexterior surface, is made of one piece of glass to prevent therefraction which would occur at the lines of angular departure of onefacet from another if the facets were made of separate pieces abuttededgewise t g ther, It is pra t c lly important. to make such flaringreflector of one piece of glass, and 'I have found that the same can bepractically manufactured at low cost with the exterior and interiorseries of angularly disposed and opposed facets. It is also practicallyimportant that the elec tric lamp should be contained within the chamberof the annular flaring or zonal reflector, and this means that suchreflector must have a recess in its brim for reception of the lampsocket if the most effective conservation of light rays is to beeffected in motion picture projection and photographic enlargementorother operations.

The lines 00 indicate reflected light rays that pass, in parallelismthrough the condenser lens and then converge at a focal point at thecenter of the usual objective lens 33* after passing through a filmpositioned at 34 as usual in motion picture projection. Y

If the reflecting surface of the reflector brim were either in the arcof the circle of the spherical portion of the reflector, or curvedinwardly, numerous rays instead of being reflected into the condenserlens as shown, would not pass properly through the condenser lens. 'Butthe brim may be omitted although it is economically desirable to retainit for the conservation. of all the rays that by seeming possibility canbe conserved for passage in parallelism through the condenser lens. p iY Various changes can be made from'what are set forth above as differentforms of my invention, without departure from it. 7

Some important advantages of my new spherical zone, reflectorindependently of its integral brim, and when combined with a parabolicmirror and incandescent lamp are the apical junctions of the adjacentintegral facets 32, which junctions are indicatedby the lines 33 whichseverally extend from the smaller back opening ofthe spherical zonereflector to its larger front opening, are severally continuous in astraight line. each being at the apex of a series of interiorly acuteand exterior-1y obtuse, annular-ly-disposed adacent integral facets; theseries of facets be tween any two of the lines 33 being severallytrapezoidal when viewed in plan, and successively increasing in lengthfrom the smaller end to the larger end of the reflector; that is. thelocation of the facets is not such as to bring the ends of anytrapezoidal facet in an annular series thereof between the ends of atrapezoidal facet in an adjacent annular series and thereby create sucha multiplicity of irregularly-disposed angularly-ar ranged facets aswould cause the light rays reflected from the glowing images in some ofthe facets to interfere unduly With light rays emanating from glowingimages in other facets. By my integral structure of the facets I avoidth e of all interiorly circularribs of any material, such ribs if ofmetal interfering with the reflection, and if of glass causing,light-ray aberration. The facets of my spherical zone'reflector are notpanesof silvered glass set in a framework as. heretofore. They. havereflecting portions of equal intensity and it is the main object of thisinvention to produce a one-piece interiorly and exteriorly facted' glassreflector wherein .the facets are reflecting portions of equal intensityand have no edge portions eX-. posed 'to the'light rays, but surfaceportions only, the interior'of the spherical zone reflector being freefromall light-ray-aberrationcausingjoints walls and :ribsso that itbecomes in use as it were uniformly incandescent: a

What I claim is:

1. 'As a new article of manufacture, an annular reflector comprising aspherical zone and a therewith-integral outwardly fiaring iconoidalbrim, the exterior and in terior surfaces being: each formed with aplurality. of annular series of facets which areangularly. disposed oneto another; the

facets in eachannular series being severally angularlydisposed to afacet in a contiguous series; andthe spherical zone portion of thereflector measuring abo1it43 from its least to its greatest diameter;and its smaller end openingsubtending an arc of about 64; the integralfacets being of trapezoidal shape and the angularly disposedadjacentends of thefacets in-each series merging in a continuous apicalline-from the smaller end opening to the larger end opening of thespherical zone, and the facets being of equal reflecting intensity: 7

2; In the-structure'of claim 1, an imperforateparabolic reflector at thesmaller end of the annular reflector; the brim of the latter having alamp socket receiving space; an incandescent electric lamp; and combinedwith the reflectors, lamp and its socket, means for adjusting the,reflectors one in relation to theot-her; and means of adjusting the lamprelatively to the two reflectors.

3. A spherical zone reflector, of one piece of suitable materialptheinterior surface being formedwith a plurality of annular series oftrapezoidal facets which are angularly disposed one to the other in eachlseries, each facet in each annular series being angularly disposed to afacet ina contiguous series, each inward facet being opposed toacorrespondingexterior facet, andsaid faceted surfaces beingrof like reflector construction, jointless, free from projections, and continuouslysmooth, andsaid facets merging directly and integrally one into another.at a projectionless angle, the facets inieach annular series reflectingthe filament when incandescent; in combination with a fixture forholding an incandescent lamp with its filament Within the chamber of thereflector and such lamp;'thesaid spheri-f cal reflector having anoutwardly flaringintegral reflector brim atits larger'end, and

the brim being formed with an incandescent lamp, receiving, opening; anda parabolic reflector at the smaller end of thereflector. I

,4. "A spherical zone reflector of'one piece of suitable material, theinterionsurfaces being, formed with" aplurality .of annular serialoftrapezoidal facets which archangularly disposed one to the other in eachseries,each facet in each annular series being angularly disposedto afacetlina co'ntigu ous series, each inward facet being opposed to acorrespondingexterior facet, andsa'id faceted surfaces bein 1 of likereflector construction, jointless, ree fromprojections, andcontinuously. smooth, and said facets merging directly and integrallyone into another at a projectionless angle, all the facets in eachannular series reflecting the filament when incandescent;inicomb'in'ation with a fixture for holding an incandescen -t lamp withits filamentwithinthe chamber ofthe reflector; said rcflector h'aving arigidexterior support movably mountedin a guideway; said guideway;andfsuch lamp.

In testimony whereof I have hereuntoset my hand this 9th day ofFebruary, WILLIAM VINOENT FoLE Y.

